The Iranian and European Union flags stands in front of a poster of the Iran talks at the International Center in Vienna, where closed-door nuclear talks have been taking place this week. Associated Press VIENNA—With one month to go until a July 20 deadline, the odds of a high-stakes nuclear deal between Iran and six major powers appeared finely balanced, with senior diplomats saying this week’s talks had shown “progress” but warning that gaps may prove too wide to resolve. After five days of discussions in Vienna, top Iranian and U.S. officials demanded major concessions from the other side and there was no pretense of any sudden breakthrough. However, the negotiating teams departed Friday with a working document in hand—the first concrete advance in months. Diplomats said all sides appear committed to reach an accord and they left with plans to return July 2 for a mammoth negotiation session […]